Aeon of Justice
by BlackStarMX
Summary: A sick Sae Niijima left Tokyo to Tatsumi Port Island in 2009 for treatment, but soon found herself in an entire a new world. Seven years later, with the news of the Phantom Thieves blazing across all media, Makoto would soon discover that her sister has known all along. (Aka the Sae insert in P3 inspired by jtav) Featuring F!Minato (not Minako).


June 2009, Niijima Household.

"You're really leaving, onee-chan?"

A tearful young child sniffed in her sister's embrace. Makoto Niijima was a strong nine-year-old kid, but nonetheless still a kid. And when faced with the information that her older sister is finally leaving her for a whole year, there is but only one appropriate response. Tackle said sister and proceed to cry in her arms.

It's not like Makoto is oblivious to her sister's condition. She had overheard the conversations between her sister and her parents before, words like "asthma" and "worsening symptoms" being whispered when they thought she weren't listening. And while her sister hides her sickness very well, an occasional coughing fit hidden behind a "common cold" excuse still alerts her that her dear Sae-nee isn't as well as she is pretending to be.

She knows, if leaving Tokyo means she would become healthy again, then there's no reason for her to prevent her sister from going, even if it means she won't see her sister for at least a year. However, seeing her sister surrounded by suitcases, any last preparations being carried out, still feels surreal to her.

"I have to. Can't let myself be sick around you all the time, could I?" Sae smiles gently at her, one hand ruffling her hair. "I really hope this helps. I hate leaving you alone."

"I hope so too. I love you, onee-chan" Makoto snuggles in her sister's embrace, her face buried in her sister's long silver hair, trying to get some final feels of her.

"I love you too. Be a good kid, okay? Mom and Dad has a lot of things to worry about."

"Of course, nee-san." Makoto held up her pinky finger. "But you have to get better. Promise?"

Sae giggles, then also held up her pinky, entwining it with her sister's. "Promise."

The next day, while Sae vanishes into the train, Makoto waves until her arm is sore, but she did not cry. She wants to be strong for her sister. One of the two most important person in her life.

* * *

Nightfall.

"Our next and last station is Iwatodai."

From the last seat of the train, a silver-haired girl finally let out a sigh and get up from her seat. Standing up and grabbing her backpack and suitcase, she headed for the door of the car, taking a glance at the scenery outside.

"So, this is where I'm gonna stay for the next year."

She's the first to exit the train, and waste no time heading for the waiting area. She was told that she would be met by someone from the Kirijo Group - the company that is in charge of her staying - there, and sure enough, the second she appears at the door of the waiting area, a voice call for her name.

"Niijima-san?"

Female, around 2 or 3 years her senior, Sae deducted from the voice. Being the elder daughter of a senior police officer means you learn a lot about his job, after all. She turns her head in the direction of the voice, and was met with a red-haired girl approaching her.

"Indeed. Who am I speaking with?" Sae replies, tone neutral as ever.

"Oh, pardon me. I haven't introduced myself yet." The girl gives Sae a small smile. "My name is Mitsuru Kirijo, Vice President of the Kirijo Group. I am currently acting President anyway, since my father has been rather unwell recently."

"Pleasure to meet you, Kirijo-san. Although... I doubt that the acting President of Kirijo Corp would busy herself with such a normal person like me." Sae decides to spill the beans immediately. She'd rather come clear with everything right now than be sorry later.

"Actually, I would. This project has been one of great interest of the group, and I'd like to supervise it personally. Also, I am currently studying here, so it would make sense for me to be your reception."

Sae nods. The logic is perfect after all. By her estimation, Kirijo-san would only be a couple of years ahead of her, so she should only be a first or second-year student at university. That leads her to another question.

"I can understand the first part, however, I doubt that a university on this island would be one that the heiress of Kirijo Group goes to?"

"University? No, Niijima-san, I am still a high school student, not a college student. I'll be one next year, though."

 _"She's only a high school student?"_ Sae was surprised by the revelation.

"Now, should we go? You can ask more while we're inside the car, I'm practically your guide here." Mitsuru turns on her heel and walk towards a black car parking right outside the station. Sae immediately followed suit.

* * *

"Kirijo-san, I think we have passed the hospital." Sae noted.

Surprisingly, the driver still keep running, even though Mitsuru has raised an eyebrow which means she has noticed her. So why didn't they stop at the hospital?

"I know. But the hospital is not out destination. You will be staying with me at our dormitory in Iwatodai."

"And why is that?" Sae asked.

"Call it a more cost-efficent way of ultilizing space. Plus, you would still attend school while the treatment's underway, so I think it would be unbeneficial for you to stay in the hospital. Don't worry, I have recently equipped our dorm with most of the medical equipment you may need." The heiress answered, her hand still tapping in her phone.

"Hmm. Fair enough." Sae replies.

* * *

Iwatodai Dormitory

"Here we are." Mitsuru exclaimed as both girls exit the car.

"Your room would be at the second floor. I'll have my driver bring the suitcase up for you."

"Thank you, Kirijo-san. Are there more people staying here? I don't believe a building this size would only have two residents."

"There are actually five more person. They should be asleep at this point, so I will introduce them to you tomorrow morning, okay?" Mitsuru's voice sounds rather relaxed at this point.

Sae nods to the red-haired girl, then turns toward the staircase. Mitsuru immediately rush forward when she sees Sae staggers.

"Here, let me walk you to your room. You must be tired."

"Thanks..." Sae breathes weakly. She is really tired after all.

* * *

Dark Hour

Mitsuru is sitting at the kitchen table. Across her sit a blue-haired girl, wearing a black uniform jacket, a black dress and white blouse. On her hips rest a sheath, slightly curved, a hilt standing out at the end.

"How was today?" Mitsuru asked.

"Tiring, as usual. Got a new sword for Junpei though."

"I noticed. Well, I should notice you that there is a new person here."

"Another persona user, Mitsuru-senpai?" The blue-haired girl raised her voice a little.

"We're not sure, but maybe. That's only one part of the reason though. She is also a patient of the Kirijo Corp. We're testing a new asthma treatment."

A moment of silence pass, but not an uncomfortable one.

"Welp, I'm going to bed." The blue-haired girl says, getting up in the process. "Let's hope her awakening, if any, is not as bad as mine." She joked a liitle.

"I think none of ours was as bad as yours, and none should be... Minato."

* * *

Welp, that's chapter 1.

This is my inspiration for f!Minato: (9)gag/com/gag/aN1qn24.

R&R would be appreciated greatly! Thanks a bunch!


End file.
